So you want to buy a 3D printer? Read this guide before you go shopping.
1. What do you want to print?
We recommend you first think about what you wish to 3D print because that will influence your printer choice.
It will have for example an impact on the size of your printer, more precisely on the build volume or the size of the build area of your printer – if the things you print have to be built in one piece, the build volume of the printer is the limit.
So head over to Thingiverse, i.Materialise, Sculpteo or Shapeways to get some inspiration.
2. How much stuff do you plan to print?
The price range for a decent filament 3D printer starts at $300 and goes up to $3,000; 3D printers using other materials cost $2,000 and more. So, it might be cheaper to use 3D printing services and networks such as 3D Hubs, i.Materialise, Sculpteo or Shapeways to get your stuff printed.
Just calculate what you wish to print in the next 6 to 12 months – and don’t forget to add shipping cost and VAT. Contrast that to the price of the 3D printer plus the material plus electricity (plus a number of misprinted objects). When will you reach break-even?
Why calculate just 6 to 12 months? Because the 3D printer market is developing at an incredibly fast pace; prices are constantly going down, more and more features are added to each new model.
3. What is your budget?
Right now, the least expensive 3D printers are those using FDM technology (filament deposition manufacturing).
* Entry level printers range from $300 to $1,300. They are the typical entry points for 3D beginners. They use standard filament, can print one color/material at a time, and have small build area.
* High-end printers range from $1,000 to $3,500. Some of them can print two colors/materials at a time; they usually print at finer resolution to get smoother surfaces. Moreover, the build area is larger so you can print larger objects.
* FDM printers that use other materials than plastic cost $2,000 and more.
* If you are good with your hands and tools you may buy a printer kit and assemble the printer by yourself. Prices start at $100 and go up to a few hundred dollars.
More expensive printers use SLA (stereolithography) or SLS (selective laser sintering) technologies:
* SLA printers use a laser or digital projector and photosensitive resins. The laser/projector causes the resin to solidify. This way, you can print objects in finer detail. Printing is faster than with FDM printers. However the resins are quite expensive (resins for the Form 1+, e.g. , cost $140 per liter), and there is only a limited choice of colors at the moment. Printers cost $3,000 and more. Recently, there was a Kickstarter campaign for the MoonRay SLA printer that will cost about $2,500 when it comes to the market in October.
* SLS printers use powder that is solidified by a laser. There is a wide variety of usable materials, e.g. metal, glass, ceramics. These printers are able to print multicolor objects. Prices start at $10,000.
4. What materials do you want to use?
The most widely used material in 3D printing is plastic, more precisely: thermoplastics. It becomes soft and malleable when heated and hard when cooled down.
There are two kinds of thermoplastics for 3D printing:
* PLA (PolyLactic Acid) is made from corn starch. It is well suited for small household items. It is available in a number of colors and is biodegradable. Also: It cools quickly, so there will be less problems with warping. However, it has a low melting point and may deform under high heat. It is also difficult to produce highly detailed objects.
* ABS (Acrylonitrile Butadiene Styrene) is made from petroleum. Objects printed in ABS are flexible and strong – just like Lego bricks. It has a higher melting point than PLA and will less likely deform under heat. It is also easier to create interlocking pieces using ABS than with PLA. On the other hand: ABS takes longer to cool down, so the models are more susceptible to warping. And ABS may emit fumes during printing.
If you wish to print metal, ceramics or glass, you need a special printer, a SLS model. But there are also wood, metal and other materials available for PLA and ABS printers: They are usually mixed with PLA or ABS: 70% PLA or ABS plus 30% metal powder, for example; more in this background article on All3DP.
Special 3D printer features you should consider
5. Build area/volume
The build area of the printer determines the maximum size of an object that can be printed in one piece. The volume is measured in XYZ dimensions: X= width, Y = depth, Z = height. We wouldn’t go with a printer with less than 5 x 5 x 5 inches (13 x 13 x 13 cm).
Of course, many objects can be split into several parts that are printed individually. You have to combine them after printing. If the parts are made of plastics, glueing them together will be no hassle.
6. Printing in one color or two (=one or two extruders)?
Most 3D printers have one extruder. The extruder is the point where the filament is melted and output to create the printed object. One extruder means that you can only print one color (or material) at a time. In order to change color during printing you have to halt the printer and exchange the filament spool to print a second color (or material).
Some 3D printers, typically the more expensive ones, have two extruders so you can print two colors (materials) simultaneously, e.g. the Makerbot Replicator 2X and a number of models from Flashforge. Some printers can be equipped with a second extruder, e.g. the Dual Extruder Tool Head from LulzBot (but that costs almost $500) or the still experimental Ultimaker Dual Extrusion Kit ($200).
7. Filament width
Desktop 3D printers typically use plastic filament. This is available in two width: 1.75 and 3 mm; most printers use the 1.75 mm filament. That means that you have a wide choice of filaments from several manufacturers. A 1kg spool costs about $20-30. A few manufacturers, e.g. Cubify, use proprietary cartridges that are a bit more expensive (but easier to handle than spools – Cubify says).
Please note that the print quality and layer thickness do not depend on the filament width – layer thickness is determined by the printer’s extruder not the filament diameter.
8. Layer thickness (or vertical resolution)
This is the minimum thickness of a layer that the printer produces in one pass. The smaller the layer thickness, the smoother the printed object will be. However, printing will last longer as the printer has to output more layers.
Typical consumer FDM printers have a layer thickness of 0.2 or 0.3 mm, more expensive ones even 0.1 mm. Some allow you to adjust layer thickness so you can print drafts at higher speed.
SLA printers print layers as thin as 0.03 mm.
9. Horizontal resolution (X and Y)
The horizontal resolution indicates the minimum movement the extruder can make within a layer. The smaller the value, the higher the level of detail the printer produces. XY resolution should not be more than 0.3 mm.
10. Heated bed vs. non-heated
A heated print bed will dramatically improve print quality because it keeps the extruded plastic warm during the entire printing process and prevents warping. Warping is an unwanted effect caused by plastic cooling down faster along the edges compared to the inside. This way the edges will warp up and deform the object.
Less expensive 3D printers usually have no heat bed as that adds to the cost of the printer. However, some manufacturers offer optional heat beds you can add.
Please note: If you have an unheated print bed, you can minimize warping by adding a raft underneath the object. The raft increases the surface of your printed object and improves the object’s adhesion on the print bed.
11. Print speed
The more you print, the more important print speed will become – your printouts will be finished faster. Print speed depends on the printer itself, but also on the material used and on the complexity of your objects.
Look at the printer specifications: The printer speed indicates how fast the printer can move its extruder. However, there are other factors that influence printer speed, e.g., the acceleration and deceleration of the printer – however, manufacturers usually do not specifiy these values.
12. Other printer features worth considering
If you plan to put the 3D printer in your office, you better factor in these features:
* size and weight
* heat emission
Also: Do you plan to often take the printer with you (to trade shows, to customers, to your weekend resort)? Then weight, transportability and ruggedness will be of importance.